NESTING NICHE PARTITIONING BY WHITE-WINGED AND MOURNING DOVES WITH OBSERVATIONS OF OTHER SYMPATRIC COLUMBIDS THESIS Presented to the Graduate Council of Texas State University-San Marcos in Partial Fulfillment of the Requirements for the Degree Master of SCIENCE by Kenneth A. Ruiz, B.S. San Marcos, Texas August 2012 NESTING NICHE PARTITIONING BY WHITE-WINGED AND MOURNING DOVES WITH OBSERVATIONS OF OTHER SYMPATRIC COLUMBIDS Committee Members Approved: ________________________________ John T. Baccus, Chair ________________________________ Michael F. Small ________________________________ Floyd W. Weckerly Approved: ______________________________ J. Michael Willoughby Dean of the Graduate College COPYRIGHT by Kenneth A. Ruiz 2012 FAIR USE AND AUTHOR’S PERMISSION STATEMENT Fair Use This work is protected by the Copyright Laws of the United States (Public Law 94-553, section 107). Consistent with fair use as defined in the Copyright Laws, brief quotations from this material are allowed with proper acknowledgement. Use of this material for financial gain without the author’s express written permission is not allowed. Duplication permission As the copyright holder of this work I, Kenneth A. Ruiz, authorize duplication of this work, in whole or in part, for educational or scholarly purposes only. ACKNOWLEDGEMENTS I thank all who helped me complete my research. Dr. Michael Small and Dr. John Baccus provided me with invaluable information on doves and their behavior. Dr. Michael Small helped with design and logistics of my project. Dr. Floyd Weckerly assisted me with statistical and analysis of the data for this project. I would also like to thank the staff at Estero Llano Grande State Park for giving me complete access to the park and allowing me to stay on the grounds. The staffs at Aquarena Springs and the Texas State Golf Course were gracious in allowing me to search their grounds for nests. The staff of the San Marcos Baptist Academy and the San Marcos Cemetery provided me access to their properties as well. The Texas Parks and Wildlife Department supported my research through the White-winged Dove stamp proceeds. I would also like to thank family and friends for supporting me during my academic career. This Manuscript was submitted on July 16, 2012. v Table of Contents Page ACKNOWLEDGEMENTS .................................................................................................v LIST OF TABLES ............................................................................................................ vii ABSTRACT ....................................................................................................................... ix CHAPTER I. Introduction ..................................................................................................1 II. Materials and Methods .................................................................................4 Data Collection .......................................................................................5 Statistical Analysis ..................................................................................7 III. Results ..........................................................................................................9 IV. Discussion ..................................................................................................12 APPENDIX ........................................................................................................................15 LITERATURE CITED ......................................................................................................26 vi LIST OF TABLES Table Page 1. Multivariate analysis of variance results of nest characteristics between White-winged Doves and Mourning Doves for both Estero Llano Grande State Park and San Marcos, Texas. ..................................................................15 2. Individual analysis of variance results for each nest characteristic for White-winged doves and Mourning doves in Estero Llano Grande State Park during summer 2009 ........................................................................................15 3. Individual analysis of variance results for each nest characteristic for White- winged Doves and Mourning Doves in San Marcos .......................................16 4. Hurlbert’s Standardized Niche Breadth for both White-winged and Mourning Doves in Estero Llano Grande State Park ........................................................16 5. Hurlbert’s Standardized Niche Breadth for both White-winged and Mourning Doves in San Marcos .......................................................................................17 6. The values of all nest parameters for White-winged Dove nests in San Marcos during summer 2010 ........................................................................................18 7. The values of all nest parameters for Mourning Dove nests in San Marcos during summer 2010 ........................................................................................20 8. The values for all nest parameters for White-winged Dove nests in Estero Llano Grande State Park ..................................................................................21 vii 9. The values of all nest parameters for Mourning Dove nests in Estero Llano Grande State Park ............................................................................................22 10. The number of available nesting trees at the study sites in Estero Llano Grande State Park ............................................................................................23 11. The number of available nesting trees at the study sites in San Marcos..........25 viii ABSTRACT NESTING NICHE PARTITIONING BY WHITE-WINGED AND MOURNING DOVES WITH OBSERVATIONS OF OTHER SYMPATRIC COLUMBIDS by Kenneth Alfredo Ruiz, B.S. Texas State University-San Marcos August 2012 SUPERVISING PROFESSOR: JOHN T. BACCUS White-winged (Zenaida asiatica), Mourning (Z. macroura), White-tipped (Leptotila verreauxi), Inca (Columbina inca), and Common Ground (Columbina passerina) doves commonly nest in the same environment in South Texas, and White-winged, Mourning, and Inca Doves nest in the same environment in central Texas. Differences in nesting behavior and dimensional aspects of the nesting substrate chosen by these sympatric dove species have not been thoroughly studied. My study provides comprehensive analyses of active nests for these doves in two distinct study sites: Estero Llano Grande State Park in the Lower Rio Grande Valley (LRGV) and the City of San Marcos in central Texas. I hypothesize that discernible and substantial differences exist in nest location and habitat ix among these species. Doves nested in distinct habitats in Estero Llano Grande State Park. There was a significant difference in nest height in Estero Llano Grande State Park between White-winged and Mourning Doves. There were no differences in nesting characteristics for doves in San Marcos. White-winged and Mourning Doves may be partitioning space for nesting in Estero Llano Grande State Park because both species have historically nested together in that area as opposed to the more recent expansion of White-winged Doves into central Texas. x CHAPTER I INTRODUCTION Studies of niche partitioning in doves have addressed food habits and foraging activities (Rivera-Milãn 1993, 1996, 2001; Wolf et al. 2002; Sol et al. 2005; Hayslette 2006) and vocal activities (de Kort et al. 2002; Kopij 2003) in dove species. Nesting behaviors and partitioning of space among dove species (Columbidiae) using similar resources have not been thoroughly researched (Cunningham 1997). A multitude of factors ranging from risk of predation to interspecific competition for available resources may influence nesting habitat selection by dove species. Nesting preferences are difficult to determine and may also vary by habitat. Five species of native doves breed and nest in Estero Llano Grande State Park in south Texas: White-winged (Zenaida asiatica), Mourning (Z. macroura), White-tipped (Leptotila verreauxi), Inca (Columbina inca), and Common Ground (Columbina passerina) Doves. Three species, White-winged, Mourning and Inca Doves, breed and nest at San Marcos in central Texas. Highest nest densities and nesting success of White-winged Doves historically occurred in dense, mixed woodlands dominated by Texas ebony (Ebenopsis ebano) in Tamaulipas Mexico and the Lower Rio Grande Valley (LRGV) of Texas (Cottam and Trefethen 1968; Schwertner et al. 2002). Recently, White-winged Doves have expanded their range from the LRGV northward and eastward in Texas to urban environments (Glass et al. 2002; Schwertner et al. 2002). 1 2 Mourning Doves nest in a wide array of ecological types throughout North America. A precise description of breeding habitat is difficult because of the broad adaptability of this species. Generally Mourning Doves avoid dense woods or extensive forest and select more open woodlands and edges between forest and prairie biomes for nesting (Tomlinson et al. 1994). Mourning Doves use a variety of coniferous and deciduous trees, shrubs, vines, man-made structures, and the ground for nesting. Heavy use is made of honey mesquite (Prosopis glandulosa) and ground nesting in central North America (Eng 1986; Sayre and Silvy 1993; Mirarchi and Baskett 1994). White-tipped Doves in south Texas and northern Mexico historically occupied native riparian vegetation along the Rio Grande. Native vegetation in these areas is characterized by Texas ebony, cedar